The manufacture of integrated circuits (ICs) is a multi-step process carried out on a wafer or a mask, which can be generally referred to as a substrate. Multiple ICs are typically produced on each wafer and each IC can be inspected for defects. Defect inspection is one step of the manufacturing process of ICs. Inspection systems can detect defects that occur during the manufacturing process. Optical wafer/mask inspection systems have been conventionally used for wafer/mask inspection. High-resolution inspection systems also exist for substrate inspection.